Propeller.



C. M. BERRY.

, PROPELLER.

APPLICATION FILED JULY 31,!915. RENEWED DEC-6.1916.

Patented-June 5, 191?.

' CHARLES a; BERRY, or new YoRK, N. Y., AssIGNoR TO THE REINFoRonD PRO- PRLLER AND INSULATING on NEW YoRK.

I Application filed July 31, 1915, Serial No. 42,907.

To all whom it may concern: I

Beit known that I, CHARLES M. BERRY, a citizen of the United States, residing at New York city, New York, have invented a new and useful Improvement in Pro.- pellers, of which the following is a specification.

This invention relates to propellers for use in connection with aeroplanes, steamboats and the like, the object being to produce an article of manufacture ofthe class described, possessing lightness, strength and balance.

It is. commonly known .that the wooden propeller now in general use in connection with aeroplanes is unsatisfactory in that 'it is susceptible to climatic changes and warps readily, which condition greatly increases vibration and appreciably afi'ects the balance. My propeller aims to correct any tendency toward warping and maintainsaccurate balance indefinitely.

In 'carrying out my invention I provide stamped sheet metal propeller halves the edges being provided with suitable flanges which are adapted, when the parts are assembled, to snugly fit one'within the other and over and around this hollow structure- I place a layer of carbonaceous matter which gives the structure a finish and reinforces the same throughout and in this manner I am enabled to construct a propeller possessing great rigidity and light-' ness and which wil always retain its given shape and balance under any and all conditionsof use.

In the drawings: Figure 1 is a' face view of a propeller constructed, according to my invention, partly broken away to show the interior. Fig.2 is an enlarged cross section taken at 22, through oneof the blades and showing a mold employed in the manufacture'of the propeller. I

Fig. 3 is enlarged section taken on the line 3'.-3.of Fig. 1.

Referring to the drawings 1 show at 10, I

Specification of Letters Patent.

COMPANY, INC., 015 NEW YORK, N. Y., A CORPORATION I 'rRoPnLnRR.

Renewed December 6, 1916. Serial No. 135,485.

within the other, and in the form of construction shown, the flange 16, is received within the flange 15, and when the parts are assembled a hollow space 17, remains between the sections as shown.

The sections are preferably coated either with sheets, strips or plastic material of acarbonaceous nature and are then placed in a proper mold or form such as 18, and

subjected to heat and pressure after which the propeller may be removed in a finished highly polished condition and is ready for use. The finishing layer or coat just described acts to reinforce the entire structure and produces a smooth finish which is desirable in this class'of articles of manufacture. I-hav'e not described the mold 18 in detail as it forms no part of this invention and is the subject matter of co-pending application 42,906.

It will be understood that the metallic sections may be made upin quarters or any practical number of these sections may be employed and changes in and modifications of the form shown may be resorted to without departing from thespirit of my invention or the scope of the appended claim. The flanges may also be eliminated.

' Patented June 5, rear.

Having thus described my invention what I claim; and desire to secure by Letters Patent is:

A propeller constructed of sheet metal sections having marginal flanges to. form,

when assembled, a hollow structure reinforced with a coating of carbonaceous material.

In testimony whereof, I, CHAnnns M. BERRY, have signed my name to this specification, this 30th day of July, 1915.

\ CHARLES M. BERRY. 

